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Biomedical subjects

G Ia Kolomiĭtseva

Publications and source records attributed to G Ia Kolomiĭtseva.

At least 19 recordsLinked to original sources
PubMed1994

[Study of DNA-protein crosslinks induced by UV light in Hela cells].

UV-Irradiation (lambda = 254 nm) of Hela cells in the monolayer causes a dose-dependent formation of DNA-protein crosslinks (DPC). The time-dependent protein increase unaccompanied by a change in the complex yield was observed for the fraction of the DNA-protein complex passing into the aqueous phase by phenol extraction, when the cells were transferred to a fresh culture medium after UV-irradiation. These data suggest that DPC do not repair, while DNA or the protein within the complex can firmly bind additional quantity of protein during the post-irradiation period.

Culture Media↗
PubMed1990

[Chemiluminescence in a toluene-fenoxol scintillation system in the radioreceptor method of researching biological membranes].

The scintillation toluene-fenoxol 8/10 system with ammonia (0.01%) is suggested for radioactive counting in radioreceptor biomembrane assay. It is shown that chemiluminescence in this system is defined mainly by membrane components presence. The remotion of filter from scintillator after labelled molecules elution and methanol (3%) addition to scintillation mixture are suggested to reduce the chemiluminescence level.

Ammonia↗
PubMed1987

[Localization of lysine residue in histone H3 forming the thymine-lysine cross-link after UV-irradiation of deoxyribonucleoprotein].

A thymine-modified derivative of histone H3 formed as a result of thermal treatment of UV-irradiated (lambda = 254 nm) solution of deoxyribonucleoprotein from calf thymus at low ionic strength was isolated. The peptides obtained by tryptic hydrolysis of modified histone H3 were separated by high pressure liquid chromatography. The amino acid sequence of the peptide containing a lysine residue with covalently linked thymine was determined by the Edman method. It was found that Lys localized at the N-terminus of the histone H3 molecule interacts with DNA within the composition of the deoxyribonucleoprotein.

Amino Acids↗
PubMed1986

[Characteristics of sulfhydryl groups of histone H3 from the calf thymus using mercury-containing nitroxyl radicals].

The interaction between total histone and deoxyribonucleoprotein (DNP) preparations from calf thymus with mercury-containing nitroxyl radicals in low ionic strength solutions, 2 M NaCl and urea was investigated. It was found that the label is rapidly incorporated into the SH-groups of histone H3 to produce characteristic EPR signals. Titration of SH-groups within DNP demonstrated that in low ionic strength solutions only one SH-group (presumably, the SH-group of the cysteine residue in position 110) is accessible to the reagents. After dissociation by 2 M NaCl, two SH-groups become titrable; however, the EPR spectra point to differences in the conformational state of these two groups. In 4 M urea, these differences are compensated for by structural disintegration. The spin labels may be used for the analysis of SH-groups under different conditions and at different functional states of nucleoproteins.

Animals↗
PubMed1986

[Measurement of the 125I and 14C radioactivity in double-labeled blood samples].

A method for detection of 14C and 125I radioactivity in labeled samples with variable quenching using only liquid scintillation counter is described. Precision, sensitivity and reproduction of this method are comparable with those of the previously used ones, but this method is more suitable and adequate for computerisation.

Animals↗
PubMed1985

[The role of histones H3 and H1 in the formation of thymine-lysine cross-links during UV-irradiation of deoxyribonucleoprotein].

The effect of UV light (lambda = 254 nm) on calf thymus DNP at low ionic strengths was studied. It was found that at the irradiation doses used the protein in the DNA-protein complex increases as the irradiation dose rises. Thermal treatment and acid hydrolysis resulted in a predominant release of histones H3 and H1 from the complex. Data from liquid high performance chromatography, amino acid analysis, thin-layer chromatography point to the induction by UV-light of a thymine-lysine bond, whose formation involves DNA thymines and histone lysine residues, predominantly H3 and H1 fractions.

Animals↗
PubMed1982

[Comparative enzymatic study on the structure of chromatin in the nuclei of the growing microplasmodium of Physarum polycephalum].

The structure of chromatin in the growing myxomycetes P. polycephalum can be interpreted on the basis of three types of substructure: (i) soluble in a low ionic strength buffer and 2 mM EDTA (I), (ii) soluble in 0.6 M NaCl (II) and (iii) non-soluble and nuclease-insensitive (III). The ratio of these structures in the nuclear pellet obtained after autolysis was found to be 71 : 0, 4 : 12 for the young and 7.7 : 62 : 20.6 for the old cultures, respectively. The ageing of the culture involves transition of substructure I to substructure II. The substructures differ in the nuclease sensitivity. The specific features of enzyme fragmentation of chromatin from P. polycephalum microplasmodium nuclei are discussed.

Cell Nucleus↗
PubMed1982

[UV-light-tested protein--DNA interactions in the nuclei during the cell cycle in Physarum polycephalum].

The release of DNAs from nuclear preparations isolated at different steps of the cell cycle of the synchronous culture of Physarum polycephalum and irradiated with UV-light for 5 min (lambda 253.7 A, i = 1.8 . 10(2) j . m-2 . min-1) into 1% Na-DS - 1.5 M NaCl solution was studied. The value obtained correlated well with the degree of binding of interacting proteins with DNA in chromatin and was identical for all the preparations tested with the only exception of the nuclei isolated at the end of the S-phase, when a slight but significant (15 +/- 10%) increase in DNA release was observed. The results obtained are discussed in terms of structural transitions and function of chromatin during the cell cycle of the myxomycete Physarum polycephalum.

Cell Cycle↗
PubMed1982

[Comparison of endogenous nuclear RNA-polymerase II at different stages of mycoplasmodial growth].

The nuclei of Physarum polycephalum isolated from the 48- and 96-hour-old growing microplasmodium differ 7-8 fold by the rates of [3H]UTP incorporation in vitro accompanied by a slight (approximately 1.6 fold) change in concentration of endogenous RNA-polymerase II. Using mild fragmentation of chromatin nuclei by micrococcal nuclease and DEAE-Sephadex chromatography the bound enzyme was shown to consist of two forms differing in the degree of their binding to the template and in functional significance. Transcription in the Physarum polycephalum nuclei can be regulated by changes in the correlation of these forms.

Cell Nucleus↗
PubMed1979

[Effect of UV-light on the structure of soluble deoxyribonucleoprotein-200 A].

The effects of UV-light (253,7 nm) on the structure of DNP and its protein and nucleic components were studied. The formation of protein-DNA covalent bonds in DNP-200 A at low ionic strength was confirmed. Under certain irradiation conditions more than 80% of protein may be linked to the DNA; all histone fractions were linked to the same extent and at the same rates. The local denaturation of DNA in the region of photo-induced thymine-thymine dimers and other photoadducts dramatically changed the rate and specificity of the effects of staphylococcal nuclease, which directly affected the composition and size of the fragments formed. A possible application of UV-irradiated DNP for various structural investigations is discussed.

Animals↗
PubMed1978

[Reaction between tetranitromethane and deoxyribonucleoproteins].

A comparative kinetic study has been made of tetranitromethane nitration of tyrosine residues in deoxyribonucleoprotein preparation (DNP) treated with EDTA and/or UV light at lambda=253.7 nm, as well as obtained by enzymatic digestion of nucleosomes. UV-light-induced protein-DNA linkages stabilize the structure of the preparation, whereas the action of chelate agents causes DNP-200 angstrom leads to DNP-100 angstrom transfer. Comparison of kinetic data and the results of the amino acid analysis of individual fractions of nitrated histones allowed to conclude that the differences observed between the degree and the rate of nitration are due to internucleosomic interactions which form the supernucleosomic structure of DNP.

Chemical Phenomena↗